234 LECTURE X. 



You see, gentlemen, the microscope solves the difficul- 

 ties in a very simple manner, by demonstrating that this 

 mass, which looks like pus, is not pus. For we under- 

 stand by pus a fluid essentially provided with cellular 

 elements. Just as little as we can imagine blood with- 

 out blood-corpuscles, just as little can pus exist without 

 pus corpuscles. But when, as in the present instance, 

 we find a fluid which is nothing more than a mass per- 

 vaded by granules, this may indeed, as far as external 

 appearance goes, look like pus, but never ought to be 

 regarded as real pus. It is a puriform, but not a puru- 

 lent substance. 



But now we frequently see that in addition to these gra- 

 nules a certain proportion of other structures show them- 

 selves, for example, really cellular elements (Fig. 70, B), 

 which are round (spherical), or angular, present one, two, 

 or more nuclei, frequently lie tolerably close to one an- 

 other, and in reality exhibit a great similarity to pus- 

 corpuscles, the distinction at most being that very often 

 fat-granules occur in them, indicating that a process of 

 disintegration is going on. Whilst therefore in individual 

 cases there can, on account of the often very greatly pre- 

 ponderating mass of debris, exist no doubt as to what the 

 observer has before him, in others considerable doubts 

 may exist as to whether real pus is not present. These 

 doubts cannot be removed in any other way than by an 

 examination into the history of the development of the 

 puriform mass. Now that we have already seen that 

 colourless blood- and pus-corpuscles perfectly agree with 

 one another in form, so that it is impossible to draw a 

 real distinction between them, the question which sug- 

 gests itself in cases where we find round, colourless cells 

 in a clot of blood, whether these cells are colourless 

 blood- or pus-corpuscles, can only be decided by deter- 

 mining whether the corpuscles were present in the 



